The novel immobilization of G-quadruplex aptamer on Cu deposited surface using electrochemical method

A simple and novel method for immobilization of AS1411 aptamer, on Cu nanoparticles (NPs) electrode has been presented. For the first time, AS1411 aptamer without any functionalization was successfully immobilized on the Cu-NPs coating because of the interaction between guanine and Cu(111). The electrochemical responses determined that the current decreased, due to the strong electrostatic repulsive interaction between the negatively charged phosphate groups in aptamer strands and [Fe(CN)(6)](3-/4-) in the electrolyte solution, leading to less electron transfer efficiency in the system and indicating the absorbance of G- quadruplex aptamer on the surface of Cu-NPs. In this work, 0.03 M was chosen as the Cu concentration, and the optimized aptamer concentration and incubation time on Cu-NPs were determined 10 mu M and 20 min, respectively. Finally, the outstanding performance of the immobilized aptamer on the Cu-NPs coated surface was confirmed by quartz crystal microbalance. This study provides a low cost and easy approach for G-quadruplex aptamer trapping on the metal surface without incorporation of any ligand which could be helpful for fast and reliable cancer diagnosis in biomedical researches. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

A simple and novel method for immobilization of AS1411 aptamer on Cu nanoparticles electrode was presented and validated by experiments. The study found that choosing 0.03 M Cu concentration, 10 μM aptamer concentration, and 20 minutes incubation time achieved the optimized performance, which was confirmed by quartz crystal microbalance.